Field of the Invention
The invention relates to an inner seal collar with improved locking mechanism for insertion into pipes, for the purpose of sealing leak points in the same.
Background of the Invention
Such internal sealing collars have been known for a long time, and are described by way of example in DE 44 01 318 C2. Using such internal sealing collars, it is possible to repair leakage points in, for example, underground pipes made of concrete or another material, without trenching. For this purpose, the internal sealing collar is inserted into the leaking pipe being repaired, up to the position of the leak. In this process, the internal sealing collar is initially spirally compressed such that it has a smaller diameter than the pipe being sealed. Once the internal sealing collar has been moved into the position of the leak in the pipe being repaired, the internal sealing collar is expanded by means of a mechanical installation device until it has come into very tight contact with the inner wall of the pipe, compressing the seal rings. The internal sealing collar is held in its expanded position by means of an arresting device which has a tensioning pinion which meshes with a toothed bar, and a spring-loading locking pinion which engages with the same.
EP 0 805 932 B1 suggests an arresting device which is improved over the above. The document discloses an internal sealing collar having an arresting device which enables very small locking steps and therefore ensures a strong, permanent contact with the inner pipe wall following its expansion, providing a strong press force on the sealing organs. The improved arresting device comprises, for this purpose, a slot arranged peripherally around the belt end on the inside, wherein a toothed bar is arranged on each of the two opposing longitudinal edges thereof. Two tensioning pinions are arranged in the slot, each of these engaging with one of the two toothed bars, and also being loaded by one locking pinion which functions as the locking organ. The locking pinion is pressed into the intermediate space between the two tensioning pinions by a tensioning spring.
An internal sealing collar having such an arresting device is in need of improvement with respect to the force load which can be achieved.
The aim of the present invention is therefore that of advancing the known internal sealing collars in such a manner that the arresting device can receive greater forces—that is, such that it is more difficult to unlock than previously.